Let me give you my itinerary so you can advice to whether to buy JR Rail pass and what type of pass:-
7DEC ARR NRT Airport , will be staying in Nishi-Shinjuku for 3 nights
8DEC Travel around Tokyo
9DEC Tokyo to Nikko- Travel around Nikko (Ninja Edo Wonderland, Nikko World Heritage)
10DEC Tokyo to Mt Fuji - Please advice best place to stay with Mt. Fuji view with a hot spring
and not too expensive. (For 2 nights)
11DEC MT Fuji-Hakone
12DEC Can suggest where to go???
13DEC Back to Tokyo or NRT
14DEC Dep by flight to KUL
Thank you